# Is there a current item ?
fun is_ok: Bool is abstract
+
+ # Iterate over `self`
+ fun iterator: Iterator[E] do return self
end
# A collection that contains only one item.
class Container[E]
super Collection[E]
- redef fun first do return _item
+ redef fun first do return item
redef fun is_empty do return false
redef fun length do return 1
- redef fun has(an_item) do return _item == an_item
+ redef fun has(an_item) do return item == an_item
- redef fun has_only(an_item) do return _item == an_item
+ redef fun has_only(an_item) do return item == an_item
redef fun count(an_item)
do
- if _item == an_item then
+ if item == an_item then
return 1
else
return 0
redef fun iterator do return new ContainerIterator[E](self)
# Create a new instance with a given initial value.
- init(e: E) do _item = e
+ init(e: E) do item = e
# The stored item
- readable writable var _item: E
+ var item: E writable
end
# This iterator is quite stupid since it is used for only one item.
-class ContainerIterator[E]
+private class ContainerIterator[E]
super Iterator[E]
redef fun item do return _container.item
- redef fun next do _is_ok = false
+ redef fun next do is_ok = false
init(c: Container[E]) do _container = c
- redef readable var _is_ok: Bool = true
+ redef var is_ok: Bool = true
- var _container: Container[E]
+ private var container: Container[E]
end
# Items can be removed from this collection
# Add each item of `coll`.
# var a = [1,2]
- # a.add_all [3..5]
+ # a.add_all([3..5])
# assert a.has(4) == true
# assert a.has(10) == false
fun add_all(coll: Collection[E]) do for i in coll do add(i)
# Because of the law between `==` and `hash`, `hash` is redefined to be the sum of the hash of the elements
redef fun hash
do
- var res = 0
- for e in self do res += res.hash
+ # 23 is a magic number empirically determined to be not so bad.
+ var res = 23 + length
+ # Note: the order of the elements must not change the hash value.
+ # So, unlike usual hash functions, the accumulator is not combined with itself.
+ for e in self do res += e.hash
return res
end
+
+ # Returns the union of this set with the `other` set
+ fun union(other: Set[E]): Set[E]
+ do
+ var nhs = new_set
+ nhs.add_all self
+ nhs.add_all other
+ return nhs
+ end
+
+ # Returns the intersection of this set with the `other` set
+ fun intersection(other: Set[E]): Set[E]
+ do
+ var nhs = new_set
+ for v in self do if other.has(v) then nhs.add(v)
+ return nhs
+ end
+
+ protected fun new_set: Set[E] is abstract
end
# MapRead are abstract associative collections: `key` -> `item`.
# var x = new HashMap[String, Int]
# x["four"] = 4
# x.clear
- # x.keys.has("four") == false
+ # assert x.keys.has("four") == false
#
# ENSURE `is_empty`
fun clear is abstract
class MapKeysIterator[K: Object, V]
super Iterator[K]
# The original iterator
- var iterator: MapIterator[K, V]
+ var original_iterator: MapIterator[K, V]
- redef fun is_ok do return self.iterator.is_ok
- redef fun next do self.iterator.next
- redef fun item do return self.iterator.key
+ redef fun is_ok do return self.original_iterator.is_ok
+ redef fun next do self.original_iterator.next
+ redef fun item do return self.original_iterator.key
end
# Iterator on a 'values' point of view of a map
class MapValuesIterator[K: Object, V]
super Iterator[V]
# The original iterator
- var iterator: MapIterator[K, V]
+ var original_iterator: MapIterator[K, V]
- redef fun is_ok do return self.iterator.is_ok
- redef fun next do self.iterator.next
- redef fun item do return self.iterator.item
+ redef fun is_ok do return self.original_iterator.is_ok
+ redef fun next do self.original_iterator.next
+ redef fun item do return self.original_iterator.item
end
# Sequences are indexed collections.
var p = 0
var i = iterator
while i.is_ok do
- if p>pos and i.item == item then return i.index
+ if p>=pos and i.item == item then return i.index
i.next
p += 1
end
return res
end
- redef fun iterator: IndexedIterator[E] is abstract
-
# Two sequences are equals if they have the same items in the same order.
#
# var a = new List[Int]
# Because of the law between `==` and `hash`, `hash` is redefined to be the sum of the hash of the elements
redef fun hash
do
- var res = 0
- for e in self do res += res.hash
+ # The 17 and 2/3 magic numbers were determined empirically.
+ # Note: the standard hash functions djb2, sbdm and fnv1 were also
+ # tested but were comparable (or worse).
+ var res = 17 + length
+ for e in self do
+ res = res * 3 / 2
+ if e != null then res += e.hash
+ end
+ return res
+ end
+
+ redef fun iterator: IndexedIterator[E] is abstract
+
+ # Gets a new Iterator starting at position `pos`
+ #
+ # var iter = [10,20,30,40,50].iterator_from(2)
+ # assert iter.to_a == [30, 40, 50]
+ fun iterator_from(pos: Int): IndexedIterator[E]
+ do
+ var res = iterator
+ while pos > 0 and res.is_ok do
+ res.next
+ pos -= 1
+ end
+ return res
+ end
+
+ # Gets an iterator starting at the end and going backwards
+ #
+ # var reviter = [1,2,3].reverse_iterator
+ # assert reviter.to_a == [3,2,1]
+ fun reverse_iterator: IndexedIterator[E] is abstract
+
+ # Gets an iterator on the chars of self starting from `pos`
+ #
+ # var reviter = [10,20,30,40,50].reverse_iterator_from(2)
+ # assert reviter.to_a == [30,20,10]
+ fun reverse_iterator_from(pos: Int): IndexedIterator[E]
+ do
+ var res = reverse_iterator
+ while pos > 0 and res.is_ok do
+ res.next
+ pos -= 1
+ end
return res
end
end
# var a = [1,2,3]
# a.append([7..9])
# assert a == [1,2,3,7,8,9]
- fun append(coll: Collection[E]) do for i in coll do push(i)
+ #
+ # Alias of `add_all`
+ fun append(coll: Collection[E]) do add_all(coll)
# Remove the last item.
#
# assert a == [20,10,1,2,3]
fun unshift(e: E) is abstract
+ # Add all items of `coll` before the first one.
+ #
+ # var a = [1,2,3]
+ # a.prepend([7..9])
+ # assert a == [7,8,9,1,2,3]
+ #
+ # Alias of `insert_at(coll, 0)`
+ fun prepend(coll: Collection[E]) do insert_all(coll, 0)
+
# Remove the first item.
# The second item thus become the first.
#
# a.insert(100, 2)
# assert a == [10, 20, 100, 30, 40]
#
- # REQUIRE `index >= 0 and index < length`
+ # REQUIRE `index >= 0 and index <= length`
# ENSURE `self[index] == item`
fun insert(item: E, index: Int) is abstract
+ # Insert all elements at a given position, following elements are shifted.
+ #
+ # var a = [10, 20, 30, 40]
+ # a.insert_all([100..102], 2)
+ # assert a == [10, 20, 100, 101, 102, 30, 40]
+ #
+ # REQUIRE `index >= 0 and index <= length`
+ # ENSURE `self[index] == coll.first`
+ fun insert_all(coll: Collection[E], index: Int)
+ do
+ assert index >= 0 and index < length
+ if index == length then
+ add_all(coll)
+ end
+ for c in coll do
+ insert(c, index)
+ index += 1
+ end
+ end
+
# Remove the item at `index` and shift all following elements
#
# var a = [10,20,30]
end
# Associative arrays that internally uses couples to represent each (key, value) pairs.
+# This is an helper class that some specific implementation of Map may implements.
interface CoupleMap[K: Object, E]
super Map[K, E]
+
# Return the couple of the corresponding key
# Return null if the key is no associated element
protected fun couple_at(key: K): nullable Couple[K, E] is abstract
+ # Return a new iteralot on all couples
+ # Used to provide `iterator` and others
+ protected fun couple_iterator: Iterator[Couple[K,E]] is abstract
+
+ redef fun iterator do return new CoupleMapIterator[K,E](couple_iterator)
+
redef fun [](key)
do
var c = couple_at(key)
# Iterator on CoupleMap
#
-# Actually is is a wrapper around an iterator of the internal array of the map.
-class CoupleMapIterator[K: Object, E]
+# Actually it is a wrapper around an iterator of the internal array of the map.
+private class CoupleMapIterator[K: Object, E]
super MapIterator[K, E]
redef fun item do return _iter.item.second
_iter.next
end
- var _iter: Iterator[Couple[K,E]]
+ private var iter: Iterator[Couple[K,E]]
init(i: Iterator[Couple[K,E]]) do _iter = i
end
class Couple[F, S]
# The first element of the couple.
- readable writable var _first: F
+ var first: F writable
# The second element of the couple.
- readable writable var _second: S
+ var second: S writable
# Create a new instance with a first and a second object.
init(f: F, s: S)
do
- _first = f
- _second = s
+ first = f
+ second = s
end
end
nitlanguage / nit.git / blobdiff